-LRB- CNN -RRB- -- A former Ford Motor Co. employee pled guilty on Wednesday to two counts of theft of trade secrets , handing them over to a Chinese competitor .

Federal prosecutors in a U.S. District Court in Detroit , Michigan , say Xiang Dong Yu -- a 49 year-old former product engineer at Ford -- used his company access to steal trade secrets .

Yu admitted to copying 4,000 internal company documents -- including sensitive Ford design plans -- prior to his departure from Ford , according to a statement from the U.S. Attorney 's office for Michigan 's Eastern District .

He then went to his new employer 's office -- Beijing Automotive Co. -- in Shenzhen , China , bringing the stolen trade secrets with him , the statement said .

Yu returned to the United States in October 2009 , it said , where he was arrested by FBI agents who searched his computer and discovered 41 Ford design specification documents .

Under a plea agreement , Yu faces at least five years in a U.S. prison and fines of up to $ 150,000 , the statement said .

`` We will vigilantly protect the intellectual property of our U.S. automakers , who invest millions of dollars and decades of time in research and development to compete in a global economy , '' U.S. Attorney Barbara L. McQuade said in the statement . `` Those who do not play by the rules will be brought to justice . ''

Yu 's defense attorney David DuMouchel declined to comment .

Yu is currently in federal custody and will face sentencing early next year .

@highlight

Former Ford employee pled guilty to two counts of theft of trade secrets

@highlight

Xiang Dong Yu faces at least five years in prison and a fine of up to $ 150,000

@highlight

Prosecutors say Yu gave Ford design specs , other secrets to a Chinese competitor

@highlight

Yu admitted copying 4,000 Ford documents , taking them to Beijing Automotive Co. .